NMR

Question 1

examples of solvents

Answer 1

Samples are dissolved in inert solvents with no 1H atoms, e.g. CCl4, CDCl3.

These solvents have no H atoms so will not give any peaks in the H NMR spectrum.

Question 2

CCl4

Answer 2

non-polar compound that is a good solvent for non-polar organic molecules

Question 3

CDCl3

Answer 3

polar covalent molecule that is a good solvent for polar organic molecules

Question 4

TMS

Answer 4

• it only gives one signal
• its signal is away from all the other H signals •gives strong signal so only a small amount needed •it is non-toxic
• it is inert
• it has a low boiling point and so can be removed from sample easily

Question 5

Splitting of peak

Answer 5

number of inequivalent H’s on neighbouring C atoms + 1

Question 6

Hydrogens bonded to a Nitrogen or Oxygen

Answer 6

Hydrogens bonded to a Nitrogen or Oxygen usually do not couple with other protons and appear as singlets on the NMR spectra